1. Field of the Invention
The present invention relates to a display including a surface light source having an optical waveguide plate, and a display panel whose rear surface is illuminated by the surface light source.
2. Description of the Background Art
As a surface light source such as backlight illuminating a liquid crystal display panel from behind, a surface light source has been known that includes a light source such as LED and an optical waveguide plate, where the light from the light source is received at an incident end face of the optical waveguide plate and then diffused and emitted. It is preferable that such a surface light source exhibits a uniform emission intensity over the whole light exit surface. A problem here, however, is that the emission intensity is not uniform in the vicinity of the incident end face.
Japanese Patent Laying-Open No. 2005-071971 discloses a surface light source configured to solve the above-described problem, where a plurality of prisms are formed at an incident end face, and the distance between the prisms adjacent to each other and the inclination angle of the prisms are appropriately adjusted. It is disclosed that a darkened portion formed near the incident end face can be accordingly reduced.
As for the surface light source disclosed in the above-referenced publication, however, improvement in uniformity of the emission intensity is insufficient. Further, leakage light from the side end face of the optical waveguide plate is not considered. Therefore, if light leaks from this portion, a problem of deterioration in light use efficiency arises.